The mother

A mother joined her husband for a family trip to a planet in the very earliest stages of its development. Her husband had wanted to go. While she wasn't interested in visiting a barren world, she humored him. After a brief period standing on the lifeless beach, her husband was ready to leave. However, their son informed them that the environmental unit of their aquarium had died, and that they'd forgotten the spare. The mother was supportive of her daughter's pleas to release the inhabitants of the aquarium into the ocean. Her husband agreed, even though it was a violation of their civilization's rules.